﻿ 水下高压气泡动态特性数值模拟
 舰船科学技术  2023, Vol. 45 Issue (20): 14-17    DOI: 10.3404/j.issn.1672-7649.2023.20.003 PDF

Numerical simulation on dynamic characteristics of underwater bubble with high pressure
JU Yuan-yuan, XIONG Zhan, ZHANG Lei, ZHAO Peng-duo, DU Zhi-peng
No.92942 Unit of PLA, Beijing 100161, China
Abstract: The dynamic characteristic of the bubble is simulated with the VOF model of Fluent, the pulsation period of the bubble and the pressure and particle velocity of the measuring point in the flow field are obtained. The effects of the initial inner pressure and radius of the bubble on its dynamic characteristic are analyzed, the results indicate that the initial internal pressure and radius of the bubble is greater, the maximum radius of the bubble is bigger, the pulsation period is longer, and the peak pressure and the maximum particle velocity of the measuring point in the flow field are greater. The initial state of the underwater explosion bubble directly influence its dynamic characteristic, so the conclusions offer significant reference for the further study of the underwater explosion bubble dynamic characteristic.
Key words: bubble     dynamic characteristic     VOF model     underwater explosion
0 引　言

1 数学模型 1.1 控制方程

 $\frac{\partial }{{\partial t}}\left( {\rho \overrightarrow v } \right) + \nabla (\rho \overrightarrow v \overrightarrow v ) = - \nabla p + \nabla \cdot [\mu (\nabla \overrightarrow v + \nabla {\overrightarrow v ^{\rm{T}}})] + \rho g + \overrightarrow F 。$ (1)

 $\nabla \cdot (\rho \overrightarrow v ) = 0 。$ (2)

 $\frac{{\partial {a_q}}}{{\partial t}} + \overline v \cdot \nabla {a_q} = 0。$ (3)

 $\rho = {\rho _1}{a_q} + (1 - {a_q}){\rho _2}，$ (4)
 $\mu = {\mu _1}{a_q} + (1 - {a_q}){\mu _2}。$ (5)

1.2 表面张力计算

 ${\overrightarrow F _{vol}} = \sum\limits_{i < j} {{\sigma _{ij}}} \frac{{{a_i}{\rho _i}{k_j}\nabla {a_j} + {a_j}{\rho _j}{k_i}\nabla {a_i}}}{{\dfrac{1}{2}({\rho _i} + {\rho _j})}}。$ (6)

 ${\overrightarrow F _{vol}} = \sum\limits_{i < j} {{\sigma _{ij}}} \frac{{\rho {k_j}\nabla {a_i}}}{{\dfrac{1}{2}({\rho _i} + {\rho _j})}} 。$ (7)
2 数值计算模型

 图 1 计算模型 Fig. 1 Calculation model
3 结果及分析 3.1 气泡动态特性

 图 2 不同时刻气泡形状 Fig. 2 Bubble shape at different times

 图 3 气泡体积分数 Fig. 3 Bubble volume fraction

 图 4 测点处的物理参数 Fig. 4 Physical parameters at the measuring point
3.2 气泡初始内压对气泡特性的影响

 图 5 气泡初始内压对气泡体积分数的影响 Fig. 5 Influence of bubble initial internal pressure on bubble volume fraction

 图 6 气泡初始内压对测点处物理参数的影响 Fig. 6 Influence of bubble initial internal pressure on physical parameters at measuring points
3.3 气泡初始半径的影响

 图 7 气泡初始半径对气泡体积分数的影响 Fig. 7 Influence of initial bubble radius on bubble volume fraction

 图 8 气泡初始半径对测点处物理参数的影响 Fig. 8 Influence of initial bubble radius on physical parameters at measuring points
4 结　语

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